Most church histories lean strongly to either Protestant or Catholic sentiments, slighting one side or the other in coverage or offering one-sided explanations of events. Shelley's 510-page book, on the other hand, is one of the most evenhanded, concise church histories I have come across.
Shelley divides the study into eight time periods from the time of Jesus and the apostles up through the present day. This makes it easy to coordinate study of the book with broader history studies.
Despite its size, this is a fast moving, fairly easy-to-read book. Shelley often uses narrative or biographical approaches to keep the writing lively. Footnotes are rather sketchy, which makes it difficult to verify information. However, Shelley does include a list for suggested reading at the end of each chapter, and it is fairly safe to assume that these are likely to be the sources upon which he has relied. Interestingly, there are three indices at the end of the book rather than one. They provide listings under the headings of characters, movements, and events. I would recommend this book to high school students and adults.
Note: I reviewed an earlier edition of this book. The publisher's website says regarding the fourth edition: "This latest edition of the book takes a close look at the rapid growth of evangelical and Pentecostal Christianity in the southern hemisphere, addresses the decline in traditional mainline denominations, examines the influence of technology on the spread of the gospel, and discusses how Christianity intersects with other religions in countries all over the world."